1. Field of the Invention
The present invention relates to a heat pipe and, more particularly to a heat pipe having at least two kinds of fibers with different melting points to constitute a fiber wick structure, which can ensure that the fiber wick structure completely adheres to an inner wall of the heat pipe.
2. Description of the Related Art
Recently, with a remarkable development of electronics and telecommunications, a high speed/large capacity system is increasingly used, so a power consumption of the system or a generated heat per unit area of the system is increased. In order to disperse and radiate the generated heat, a heat sink, a fan attached to the heat sink, or an immersion cooling system is generally employed.
The conventional cooling apparatus mentioned above have many problems such as an insufficient heat transport capacity, noisiness, and a large size of the cooling system. As a solution of the problems of the conventional cooling apparatus, a heat pipe is used. A heat pipe is a passive cooling apparatus having no noise, a good response to heat and a good transport capacity of the heat.
In general, the heat pipe is an apparatus that effectively transfers the heat without using power, even when there is only a little temperature difference between the heat source and the condenser, due to the use of latent heat caused by the vaporization and condensation of the fluid carrying heat. Furthermore, the conventional heat pipe has a wick structure, such as a screen mesh woven from fibers or a fiber bundle, arranged on an inner wall thereof, and the heat pipe uses capillary action in the wick structure to circulate the working fluid carrying heat.
In such a heat pipe, the wick structure of the heat pipe will undergo a sintering process to adhere the wick structure to an inner wall of a pipe container of the heat pipe. The wick structure is made of a kind of fiber material with same melting point in each fiber. It thus is easily melted in the sintering process, and may suffer deformation before being adhered to the inner wall of the pipe container of the heat pipe. However, these conventional wick structures all have the above problem of failing to provide a sufficient support force to ensure that the wick structure can completely adhere on the inner wall of the pipe container of the heat pipe, and so create instable capillary action and a poor heat-dissipating ability of the heat pipe.
In addition, in the past, support rods were provided to support the wick structure for solving above-mentioned sintering question. But due to the longer manufacturing time, the higher cost and the geometric structure of the pipe container parallel to the wick structure, even though the support rods will be used to insert into the inner of the pipe container as a support of the wick structure, the support rods also may be unable to insert into the inner of the pipe container because the fitting tolerance therebetween is difficult to control or the support rods may have no support effect because of the loosen thereof. Further, particularly in taking out the support rods, it is easier to make the wick structure be deformed or destroyed so as to influence the heat-dissipating effect of the heat pipe.